SPRACA7A October   2017  – September 2022 TMS320F28075 , TMS320F28075-Q1 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1.   C2000™ Hardware Built-In Self-Test
  2.   Trademarks
  3. 1Introduction
    1. 1.1 HWBIST Overview
      1. 1.1.1 HWBIST Working In-System
    2. 1.2 HWBIST Failure Response
    3. 1.3 Advantages of Using HWBIST In-System
  4. 2Using HWBIST In-System
    1. 2.1 Fundamental HWBIST Operation
      1. 2.1.1 Initializing the HWBIST Controller
      2. 2.1.2 Executing HWBIST
        1. 2.1.2.1 Executing HWBIST Micro-Run
        2. 2.1.2.2 Executing HWBIST Full-Run
      3. 2.1.3 Error Management
    2. 2.2 Managing HWBIST on Dual-Core Device
      1. 2.2.1 Semaphore Management
      2. 2.2.2 Interprocessor Communications
    3. 2.3 System Considerations When Using HWBIST
      1. 2.3.1 Interrupt Latency
      2. 2.3.2 Power Considerations
      3. 2.3.3 HWBIST Memory Requirements
      4. 2.3.4 Injecting Errors
    4. 2.4 Debugging HWBIST In-System
  5. 3References
  6. 4Revision History

1.3 Advantages of Using HWBIST In-System

There are a number of reasons to use HWBIST in a system. Five legitimate examples are shown below:

  • Validate that the C2000 device is correctly connected in the system during the initial design validation and debug of the system.

    HWBIST may be too rigorous for this aspect of prototype debug. The emulator provides simpler methods for this effort.

  • Validate that the C2000 device is still functional after being attached to the board.

    As part of the system manufacture, it is useful to know that the part has not been damaged during board manufacturing. A board manufacturing event is most likely to catastrophically damage the device, in which case the HWBIST cannot be run in-system. Additionally, the damage is most likely done to the pin driver/buffers, peripheral circuitry, or embedded memories, which are not tested by the HWBIST. It is highly unlikely that board or system manufacturing events would damage only the circuitry targeted by the HWBIST. It is uncommon for damage to occur to the device during board manufacture. However, if the device is damaged, it is good to know early so that adjustments can be made on the board manufacturing line.

  • Check whether the device has been damaged after working properly in the system. Damage to the device is most likely to occur due to one of the following causes:
    • Overstress during power up
    • Overstress during power down
    • Voltage overstress due to power supply event
    • Temperature overstress

      Running the HWBIST at system start-up addresses the first two causes. System temperature and voltage monitors address the remaining two causes

  • Monitor the device for manufacture test escapes.

    This is not an effective use for the HWBIST in the system, because the HWBIST has already been run in the device tester environment where it can be executed with significantly higher margin, both voltage and temperature. However, if the HWBIST does capture a failure, this is a cause for concern that something in the system is operating well outside the operating range defined in the data sheet. This may not be measurable at the pins of the device, because it may be a momentary event.

  • Monitor the device for degrading mechanisms.

    Some level of transistor degradation is normal and expected with use of the circuitry. This is minor and the design and device testing includes a margin to compensate for this drift.

    Additionally, there are some latent defects that are not screenable with normal device testing methods. These defect mechanisms require some level of stressing to accelerate failures. Stress testing is used in the device manufacturing test to accelerate the majority of these degrading defect mechanisms.

    Lastly, the HWBIST helps identify these degrading mechanisms that escape the aggressive device manufacture testing.